Mechanical pencil



W. O. PONATH MECHANICAL PENCIL Nov. l1, 1941.

iled Dec. 25, 1959 2 Sheets-Sheet l INVENTOR Wzllzrz, Q Pana/I/ BY vd...

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NOV. y11, 1941. W, Q. PONATH 2,262,649

MECHANICAL PENC 1L Filed Dec. s, 1959 2 sheets-sheet 2 INVENTOR-M'Jla'am QPofza/ Jaw yabb-M s ATTORNEYS Patented Nov. 1l, 1941MECHANICAL PENClL William 0. Ponath, Richmond Hill, N. Y., assignor toEagle Pencil Company, Inc., New York, N. Y., a corporation of DelawareApplication December 23, 1939, Serial No. 310,765

(Cl. 1Z0-21) 4 Claims.

The present invention relates to pencils, and more particularly of theso-called clutch type. In a pencil of this general type, a clutch isclamped into lead gripping position by a threaded tip, and when releasedby the turning of said tip, permits the lead to drop out to any desiredwriting length.

An object of the invention is to provide a pencil of the above type,which is of rugged and inexpensive construction, which is made of fewparts that are not apt to become deranged or jammed in use, and that canbe readily and expeditiously assembled, which can be easily,conveniently and expeditiously set into lead released or clutchedposition, and in which the lead is effectively held in said latterposition against writing pressure.

Another object is to provide a pencil of the above type, in which thethrust of the clutch upon the lead is applied with equal effectiveness,regardless of wear in the clutch structure incurred in use, orvariations in the diameter of the lead, and in which, regardless of theforce manually applied in setting the clutch, the lead will not beweakened or broken at the clutched area.

Another object is to provide a pencil of the above type, in which thelead is effectively clutched under all conditions of use, clear to thelower extremity of the lead carrying structure, with exposure to View ofthe entire length of unclutched writing point, so that the user canreliably gauge the point to a length sufficient to resist writingpressure.

Another object is to provide a pencil of the above type, in which in therelease of the clutch for adjustment or replacement of the lead, no partof the clutch structure need or can be disassembled from the pencil, andin which the position of the clutch sleeve by which the clutch is set isdetermined by the lead without interference from any clutch stopelement.

Another object is to provide a method for afxing a metal clutch carryingsleeve to the forward end of the Wood case, which is simple,

thereon for the operation of the clutch at the point end of the pencil.

Various other objects of the invention will be apparent from thefollowing particular description, and from an inspection of theaccompanying drawings, in which Fig. 1 is a longitudinal section on anenlarged scale of a clutch pencil embodying the present invention, andshown in lead clutched position,

Fig. 2 is a View of the pencil, partly in longitudinal section andpartly in elevation, and showing said pencil in clutch releasedposition,

Figs. 3, 4, 5 and 6 are transverse sections taken on lines 3 3, 4 5, 5 5and 6 6 respectively of Fig. 1,

Fig. 7 is a fragmentary view, partly in section and partly in elevation,of an intermediate portion of the pencil,

Figs. 8 and 9 are sections showing successive steps in the assembly of ametal sleeve to the forward end of the wood case of the pencil,

Fig. 10 is a perspective of the window cap forming part of theindicating device,

Fig. l1 is a perspective of another portion of the indicating device,

Fig. l2 is a perspective of the indicia sleeve of the indicating device,

Fig. 13 is the shank of a modied form of indicia device, shown inperspective,

Fig. 14 is a perspective View but in section of the cap element for theembodiment of Fig. 13 and Fig. 15 is a View similar to Fig. 12 ofanother modification.

Referring now to the drawings, the wood barrel or case Il), preferablyof the usual hexagonal cross-section, has an axial bore ll of diameterslightly larger than that of the large diameter long lead I2 used insuch pencils.

The lead clutching assembly hereinafter described more fully, includes atubular clutch sleeve 25 made from a single piece of tube stock,desirably of stainless steel and having a pair of diametrically opposedslots 29 longitudinally thereof to its forward end, to forma pair ofopposed clutch jaws `3l). Each of jaws 30 is conformed at its inner faceas a cylindrical segment, on a radius not smaller and desirably slightlylarger than the radius of the lead, so that said lead will' be engagedby the inner surface of said jaws which are preferably corrugated, asfor instance by threading at 3|, to enhance the lead gripping action ofthe jaws 39. Thus the lead is not engaged by the longitudinal side edgesof the jaws, so that there is no hindrance to the free fall of the leadin open jaw position.

The clutch sleeve 25 is roughened externally at its carrying shank 26.Preferably such roughening is in the form of threads with knurls 26longitudinally of the clutch sleeve and across the threads. The threadedshank 26 is of outer diameter such, that it may be readily introducedinto the initially somewhat larger diameter o the lower end of bore II.

Thereupon, the wood of the casing is securely clamped about the clutchsleeve shank with such pressure as to force the ber of the wood snuglyinto engagement with the threads and knurls of the clutch sleeve. Thiscompression is'preferably effected in the operation of applying to theforward end of the wooden barrel a soft metal ferrule I3 preferably ofaluminum.

The ferrule I3 which is hexagonal along its main length and presentssides I4 as shown in Fig. 2, and is cylindrical and reduced at itsforward end as at I6 beyond shoulder 20 has an initial bore somewhatvlarger than the diameter of the wood as best shown in Fig. 8. A die,shown at 22 is then drawn longitudinally over the ferrule in whichoperation, as bestl shown in Figs.

8 and 9, it reduces the diameter `of the ferrule by swaging operation tosuch extent as not only to take up the initial clearance about the woodas shownin'Fig. 8, but to force the metal ferrule into the wood, so thatupon completion of the operationas suggested in Fig. 9, the outersurface of the ferrule comes substantially flush with the outer wall ofthe wooden barrel therebeyond. The wood has thus been reduced indiameter at the portion encircled bythe ferrule to an extent equal tothe thickness of the metal of the ferrule. In this operation the ferrulesleeve has been elongated somewhat as suggested in Fig. 9 and theshoulder 23 has been formed in the wood, which is abutted by the rim ofthe ferrule. 'I'he reduction in diameter of the` wood in the applicationof the ferrule has resulted in forcing the fiber thereof snugly aboutthe thread 26 and into the milled or knurled grooves 25 of the clutchsleeve shank, which served as the mandrel in the foregoing drawingoperation.

By-the construction set forth, the clutch sleeve is firmly secured withrespect to the wooden barrel, so v.that it isretained by the threadsagainst longitudinal displacement and by the knurls against rotarydisplacement relative to the barrel.

The forward end I8 of the metal ferrule I3 preferably extends forwardbeyond the forward end of the wood `case I and is further reduced indiameter to provide an annularl shoulder I9 engaging said barrel end andprotecting it against possible fracture.

Frictionally embracing an intermediate portion of the clutch member 25is a tip screw 32, made desirably of brass, and 'firmly held againstaxial movement between the forward end of the sleeve I3V and an annularradial flange 33 formed on said clutch member. 'Ihis tip screw 32 isdesirably tapered at its forward end 34 to Yfacilitate slip-` pagethereover of a'tip 35 in the assembly of the pencil.

The tip 35, desirably of stainless steel, has a cylindrical section 36threaded over the tip screw 32, and a forward end section 3'I taperingrtowards a-clutch clamping rim 38. The tip screw 32 has a thread 39 ofcomparatively high pitch, so that the tip 35 will move axially acomparatively large distance with a small turning there` of, and saidthread is desirably left hand, so that by holding the tip 35 with theleft hand and turning the pencil barrel I0 clockwise, said tip willadvance forwardly into clutch clamping position. In order tofrictionally retain the tip 35 effectively against rotation inadjustedclutch clamping position on the tip screw 32, the high pitch threads 39are desirably of the multiple type. I have found that for a tip screw ofabout onequarter of an inch in diameter, thirty triple threads of theacme type per inch is advantageous.

To avoid an unsightly gap between the tip 35 and shoulder 20 of ferruleI3, a collar 'IU snugly encircles a step II at the base of the forwardend I6 of the ferrule I3, which collar abuts shoulder 20 and snuglyembraces the base of tip 35. De-

sirably the main cylindrical length of tip 35 is knurled at I2 fornon-slipping grip by the user.

In lead clutched position, the jaws 30 extend forwardly beyond tip 35,and are cammed together in lead gripping position against their inherentresiliency by the rim 33 of said tip when said tip is turned for forwardmovement. To provide for this camming action, the jaws 30 are formedwith a forwardly flaring cam conformation 40, and when a lead isinterposed between said jaws, they will be forcedin lead grippingposition by the clamping action of the rim tip 36 on said conformation.This lead gripping action is enhanced by the tapering of the forward endof jaws 30 to arelatively sharp rim 4I. In the absence of a lead betweenthe jaws 30, these jaws can be forced together sufliciently to permitthe tip 35 to be screwed off Oron the pencil.

In'lead clutched position shown in Fig. 1, the entire portion of thelead beyond the forward end of the jaws 3U is exposed to view, so thatthe user can determine the proper length thereof for withstandingwriting pressure tending to break said lead. By turning the pencilbarrel I0 about one-half revolution counter-clockwise with respect tothe tip 35, said tip will move lrearwardly into the position shown inFig. 2and the clutch jaws 30 will be spread apart by their inherent 7resiliency to permit the lead to be dropped out ward movement of the tip35 is limited bythe step- II of the sleeve I3. The cam conformations 4Uon the jaws are the sole means for limiting the forward movement of thetip 35 from this step member 'II for lead clutching operation. Thus theeffectiveness of the lead clutching operation will not be impaired withthe wear of the cam conformations 4l).

At the rear end, the pencil isV provided with a lead grade indicatingdevice. In order to support this device, the rear end of the wood caseI0 is provided with a reduced section 45 over which is press-tted aferruleV 46 desirably of brass. This ferrule 46 may be more assuredlysecured to the wood case by puncturing said ferrule radially inwardly atspaced points, so that the resulting barbs penetrate the wood case.

Locked over the ferrule 46 against rotation but axially removable withrespect thereto is an indicia sleeve or barrel 4'I desirably ofaluminum. For so supporting this indicia barrel 4I, the ferrule 46 isprovided on its outer side with a plurality of longitudinally extendingribs 48, three of these being shown equally spaced circumferentially.The indicia member 4l is formed with an outer polygonal conformation 50desirably hexagonal, the ats of which bear respectively differentindices 5I corresponding to lead grades,

and with an internal hexagonal bore 52 of such shape that whentelescoped over the ferrule 46 as shown in Fig. 6, thevribs 48 will besnugly and frictionally retained in alternate apices of said bore. Thisarrangement holds the indicia barrel 41 against rotary movement, whilethe frictional hold of said barrel on ferrule 46 and its ribs 48 permitsit to be axially removed and replaced by another similar barrel bearinga different range of lead grades.

Telescoped over the indicia barrel 41 is a window cap 53, having anouter lsection 54 desirably of bone and desirably provided with anornamental bead 55, and a bushing 56 desirably of brass, press-fitted ormolded in the inside of said bone section 53. This bushing 56 has anenlarged sleeve section 51 substantially the same length as that of theindicia barrel 41, with an inner hexagonal conformation slightly largerthan the outer conformation of said indicia barrel. 55 are provided withregistering window openings 58, through which the indicia I on the outerflats of the barrel 41 are selectively exposed. These openings 53 areformed by the absence of one of the hexagon sides of the bushing 56, anda corresponding portion of the outer bone covering 54.

The cap 53 may be slipped on the indicia barrel 41 in any on'e of sixrotative positions with respect thereto to expose any one of the indicia5l corresponding with the grade of the lead in the pencil. In anysetting of this window cap 53, the hexagonal conformations between saidcap and the indicia barrel 41 will positively lock said cap againstrelative rotation with respect to said barrel, so that there is nopossibility of accidental relative rotational displacement between saidmembers. The frictional hold of the outer cylindrical part of saidbushing against the ribs 45, of ferrule 46 retains the window cap 53with its bone covering 54 against coming off but permits.

the same to be axially pulled oif by the user when desired for settingor for change of the indicia barrel. Furthermore, the locking of thiswindow cap 53 on the indicia barrel 41 against rotation also locks itagainst rotation with respect to the pencil barrel I0, so that said capmay be used as a rotatable finger piece in the release or clamping ofthe clutch 21. ation is eiected by holding the tip 35 against rotationin one hand and rotating the window cap 53 in the desired direction withthe other hand.

'I'hus a draftsman may set the indicating del vice to identify the gradeof lead with which the pencil is charged, and he may reset saidindicating device to correspond to the grade of lead inserted in thepencil.

With each pencil may be supplied two indicia barrels 41, each containingits own separate group of letters or indicia 5I. For instance, one ofthe indicia barrels 41 such as that shown in the drawings may bear theindices 2B, B, HB, F, H and 2H on its respect flats, and the other maybear the indices 2H, 3H, 4H, 5H, 6H and HB on its respective ats. Theseindicia barrels 41 may be interchangeably used in accordance with thegrade of the lead used in the pencil, so that the user has available tohim a wide range of lead 5 Ais a preferred form. For this purpose aferrule similar to that shown in Fig. 11 is used and the This latteroper- The outer cap covering 54 and the bushing corresponding parts bearthe same reference numerals 45', 46 and 48 as those used in Fig. 11. Theindicia barrel 41- similar to barrel 41 of Fig. 11 is telescopedover-the ferrule 46". It is releasably locked vin position by arectangular locking tongue 60 stamped out of the ferrule 46 bylongitudinalslots 6I at opposite sides of one of the ribs and aconnecting transverse slot. This tongue protrudes slightly from the woodand acts, as shown 'in Fig. 13, to latch the rear edge of the indiciabarrel 41 upon the ferrule. 'Ihe indicia barrel may, however,l readilybe removed whenever desired by simply pressing the latch tongue 60inward against the Wood so that the indicia barrel may be readilyslipped thereover. It may be replaced by another indicia barrel such asthat shown in Fig. 12 which will become lodged in position in the mannerabove described. The Wood core 45 of course forms a stop that preventsthe latching tongue form being forced inward below the surface Aof thebarrel.

The window cap shown in Fig. 14 is desirably a hexagonal aluminum sleeve62 with the window opening 153y therein and is formed with a cylindricalextension 54 of reduced diameter, over which is telescoped and securelyheld a non-metallic button 65, preferably of bone. It is the cylindricalextension 64 that frictionally fits over ribs 48 and prevents the windowcap of Fig. 14 from working off, the hexagonal section 63 being keyedwith respect to barrel 41 against relative rotation.

Instead of the two interchangeable indicia barrels of Figs. 12 and 13,it is desirable as shown in Fig.` 15 to employ a single indicia barrel15 having one tier 16 of indicia corresponding to those of Fig. 12 and asecond tier 11 corresponding to those of Fig. 13. Thus, no extra indiciabarrel need be kept in reserve and the full choice of indications of thebarrels of Figs. 12 and 13 is available. The latch 60 of Fig. 13 wouldserve to lock the indicia barrel in placek with either tier 16 or tier11 aligned with window opening 63.

As many changes could be made in the above construction, and manyapparently widely different embodiments of this invention could be madewithout departing from the scope ofthe claims, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A pencil of the clutch type including a handle, a clutch, comprisinga pair of jaws normally held apart in lead released position by theinherent resiliency thereof, a tip screw rigid with said clutch, a tipthreaded over said screw and telescoped over the forward end of saidhandle, and means responsive to the rotation of said tip in a directionto cause forward movement thereof for pressing said jaws radiallyinwardly into lead gripping position against their inherent resiliency.

2. The method of assembling the clutch sleeve of a clutch pencil to thewooden barrel thereof, which consists in. introducing the roughened,shank of said sleeve into a longitudinal bore in said barrel,telescoping a soft metal ferrule 0f' bore larger than said barrelthereover, and swaging said ferrule onto said wood barrel by applicationof radially inward force thereon progressively along its length, tobring the sleeve substantially flush with the outer wall of said barreland thereby to compress the Wood into the roughvened surface of theshank of the sleeve.

3; 'Ihe method of assembling a clutch sleeve and a ferrul'e -to the'hexagonal wooden barrel of a lead pencil of the clutch type, whichincludes the introduction of the 'roughened outer surface of the shankof the clutch sleeve loose- ,lys into acorresponding bore of the barrel,telescoping a hexagonal ferrule with an inturned end over said ferruleand swaging said ferrule onto said wooden case `by means of a ldrawingdie having a hexagonalr die conformation corresponding to the outerconformation of said barrel, whereby the length of the ferrule -iscaused to compress the Woody inwardly for snug.

n substantially flush with the Wal1 thereof.

WILLIAM O. PONATH.

